Regarding the concern with your laptop... you may want to politely ask the TSOs if either you or they can remove your carry-ons from the belt if nothing alarmed. Specifically mention your concerns over something happening to your laptop (theft, destruction, accidents, etc) and tell them that this has happened to you in the past. I doubt that this approach will result in any assistance from them, but you never know. It never hurts to ask and see what happens.

You do have the right to have your stuff kept within sight of you when they are conducting a screening. If you're placed in an area where you can't see your stuff, they should make some accommodation. If not, ask a supervisor for assistance in resolving the matter.